Photographic camera



Nov. 30, 1937. O. RISZDORFER PHOTOGRAPHIC CAMERA Original Filed Sept. 12, 1932 finder II and the adjusting Patented Nev. so, 1937 UNITED STATES PATENT OFFICE f Divided and this application Angust 6, 1935, Serial No. 34,966. In Hungary September 12, 1931 5 Claims.

9 photographic camera in such a manner that it should require as little room as possible, the said magnet is, according to the invention, fixed on the object lens carrier in such a manner, that the said magnet surrounds the frame of 1 lens.

For this purpose, the magnet is constructed in the form of a slotted, ring arranged co-axially to the'object lens of the camera, the rotary coil of the instrument being arranged inside the slot.

.The subject oi'this application is divided out of my parent application, Serial No. 632,816, which has matured into. United States Letters Patent No. 2,013,363 dated September 3, 1935.

In describing the invention in detail, reference 25 will be had to the accompanying drawing forming part of this application wherein like characters denote corresponding parts in the several views, and in which I Figure 1 illustrates a view in perspective of a 30 camera embodying the invention and Figure 2 illustrates a detail view of a diaphragm operating mechanism showing parts associated with it, including the circuits. t

In this drawing a folding camera of the usual 35 type is illustrated, comprising the casing I and the sliding floor 2, which latter is kept in'the open position by the struts 3 The object lens standard 5 is capable of being displaced in the usual manner on the rails 4 provided on the inner 'face of the sliding floor. ,The object lens standard carries the object lens itself, behind the-front member 6 of which a laminated diaphragm consisting of four lamellae 8 fixed on a helical spring 1 is provided, an opening 9 for the passage of the light being left between the internal edges of the said lamellae. The end said spring is bent over and secured to the axle II of the rotary spool II. 'The rotary spool II is fixed by means of the links M in the slot between the two legs of the magnet I, which latter sur-. rounds the objectlcns frame in the manner of a ring and is likewise fixed on the standard I.

- The magnet carries the photo-electric cell it, the

disc 20 I01: the shutthe object ll of the helical spring 1 is fixed, whilst the other end ii of the ter. This adjusting disc is fitted with a contact id for the electric resistance is connected in' series with'the photo-electric cell i5 and with the winding of the spool i3. This arrangement enables the intensity of the current in the circuit 5 2| and therefore also in the. spool l3 to be influenced by the adjustment of the shutter speed effected with the aid of the adjusting disc 20, so that the amount ofdefiection of the spool l8 and therewith the magnitude of the opening 9 of the 10 diaphragm are dependent on the magnitude of the shutter speed adjusted in each particular case.

The described arrangement of the magnet i5 possesses the advantage, that a compact device is 7 obtained and that, in spite of the fact that a regulating device comprising a photo-electric cell, as described, has been built into the camera, it is unnecessary to increase the size of the camera I above the usual size. The arrangement described also makes it possible to insert the photo-electric device into existing photographic cameras of the usual type.

What I claim is: 1. In a photographic camera, a photographic object lens, a device for the control of light entering the camera through said object lens, a photoelectric cell, a rotary spool instrument deriving. current from the photo-electric cell, means whereby the said device is controlled by the rotary spool instrument, and a magnet for the production of a magnetic field for the rotary spool instrument, the said magnet embracing the photographic objects lens.

2. In a photographic camera, a photographic object lens, a device for the control of light entering the camera through said object lens, a photo-electric cell, a rotary spool instrument deriving current from the photo-electric cell, means I whereby the said device is controlled by the rotary. 40

spool instrument, and a magnet for the prgduction of a magnetic field for the rotary spool instrument, the said magnet being ring-like in character and located to embrace thephotographic object lens. 5

3. In a photographic camera, a photographic object lens, a device for the control of light entering the camera through said object lens, a photoelectric cell, a rotary spool instrument deriving current from the photo-electric cell, means whereby the said device is controlled by the rotary spool instrument, and a magnet for theproduction of a magnetic field for the rotary spool instrument, the said magnet. being ring-like in characterandlocatedtoembracethephoto-N ing such that thering is disposed with-its center at approximately the optical axis of the lens.

4. In a photographic camera, an objective lens, an adjustable diaphragm for regulating the efiectlve aperture of said lens, an electrical measuringinstrument for adjusting the diaphragm andineluding a coil and a magnetic field system therefor, said magnetic field system embracing the objective lens, and a light sensitive cell in circuit with and adapted to energize said instrument in 8,100,672 graphic object lens, the arrangement of parts beaccordance with the brightness of the scene to be I photographed.

ing a common support for the objective lens, the

electrical measuring instrument and the light sensitive cell.

- 6D6N' RISZDORFER. 

